Trans-thoracic impedance (TTI) measurement and evoked response electroencephalography (ER EEG) have been shown to be useful techniques to study cardiopulmonary mechanisms and cerebral function in newborn infants. On-line analysis of TTI, ER EEG, and routine clinical measurements by means of discriminant scoring and pattern recognition methods hopefully will lead to improved sensitivity and specificity in the assessment of the clinical course of infants with respiratory disorders. This approach will be used to assess risk factors that affect outcome of infants with hyaline membrane disease, Type 11 respiratory distress, and apnea, as a means to more efficient evaluation of various therapeutic measures.